Sonar Probing in Narragansett Bay

A 12-kilocycle pulsed transducer, with a 0.1 millisecond duration, is used for tracing a sub-bottom rock profile in Narragansett Bay. The short sonar pulse of high energy is produced by a capacitor discharge. Over-the-side installation of the transducer permits the use of any boat or ship for the survey work. Coherent presentation of the data on a wet paper recorder gives an instantaneous visual record. Across a north-south rock formation, a recurring rise and fall of the rock is shown throughout the sedimentary deposit.